About Configuration Zones
Configuration zones divide the Cisco Application Centric Infrastructure (ACI) fabric into different zones that can be updated with configuration changes at different times. This limits the risk of deploying a faulty configuration on the entire fabric at once that might disrupt traffic or even bring the fabric down. An administrator can deploy a configuration to a defined non-critical zone, and then deploy it to defined critical zones when satisfied that it is suitable. Similar to the way that UCS Manager functions, a configuration zone is essentially an additional "user acknowledge" type of policy that forces users to verify configuration changes before applying the changes.
You can choose one of the following deployment modes for a configuration zone:
Enabled—Pending updates are sent immediately
Disabled—New updates are postponed
Triggered—Pending updates are sent immediately, and the deployment mode is reset to the value it had before being triggered
Without configuration zones enabled, policy changes will take effect on all fabric nodes once the configuration is set and standard programming criteria are met. With configuration zones enabled, you can have these policy changes transition to a state of "postponed" until a user acknowledges the change to be applied in specific zones.
Zones can encompass an entire POD, or can encompass a subset of fabric nodes.